Question:
Drinking water in peril MTBE contaminates 48 wells in public system

Is it right?

Answer: Leaks of the gas additive MTBE from nearly 1,200 underground tank sites threaten the drinking water supply of millions of Californians, state records show.

In the Bay Area, 251 leaking tank sites pose an MTBE contamination threat to public wells.

A Chronicle analysis of data from the State Water Resources Control Board and the state Department of Health Services reveals for the first time that the fast-moving MTBE already has reached 48 wells in public water systems serving hundreds of thousands of people, including seven wells in the Bay Area -- at San Francisco's Presidio, in Montara and in San Jose -- forcing closures or expensive treatment.

The data don't include tens of thousands of private wells in California and hundreds of thousands nationwide, which aren't regulated by public agencies and thus generally aren't tested for MTBE unless nearby leaking underground tanks cause concerns.